JP2009513003A - LED with translucent heat sink - Google Patents

Abstract

  A more efficient or brighter LED assembly is constituted by a high power LED chip having a first surface and a second surface, the first surface of the LED chip being attached to a substrate, the second surface Is in intimate thermal contact with a light transmissive heat sink, which has a thermal conductivity greater than 30 W / m · K. Otherwise, the LED is in electrical contact with at least one electrical connection and a second electrical connection for supplying energy to the LED chip. Providing a translucent heat sink doubles heat transfer from the LED die, increases lifetime, increases efficiency, increases brightness, or raises these three balances Can do.

Description

Cross Reference to Related Applications Applicant hereby claims the provisional application of 60/725107 filed on Oct. 7, 2005 under the title "LED with translucent heat sink".

The present invention relates to LED solid state light sources, and more particularly to LEDs. More particularly, the present invention relates to an LED having a translucent heat sink.

Description of Related Fields including Information Disclosed under 37 CFR 1.97 and 1.98 Light Emitting Diodes (LEDs) generate light when current is applied to the device. However, not all of the power input to the device is converted to light. Most of the energy is generated as heat. When the semiconductor material is heated, the LED performance is degraded as in most electronic devices. This causes a reduction in light output (light flux), color shift, and reduction in device life. Therefore, it is necessary to efficiently remove heat from the LED chip during operation without significantly reducing the light output from the package.

  In most normal electronic circuit packages that do not emit light, the active semiconductor chip is placed between two conductive plates made of a material having a high thermal conductivity, such as copper. These plates are used as heat spreaders to efficiently remove heat from the top and bottom surfaces of the chip. The thermal energy generated by the semiconductor chip is further dissipated by a heat sink attached to the electrical plate and transported from the chip and the system. Unlike semiconductor chips for power electronics, LEDs generate light and this light must be extracted from the package. An opaque material such as copper or another metal heat sink blocks the light emitting surface of the LED. Thus, LED packages typically can extract heat only from one side of the chip, thus losing half of the effective surface area due to heat dissipation.

The present invention allows for heat dissipation on all sides of the LED without blocking emitted light by using a thermally conductive translucent material. Advantages of thermally conductive lenses include the following:
(1) The operating temperature of the LED is reduced, the efficiency of the LED is increased, and the color is stabilized and the lifetime is extended due to the small wavelength shift.
(2) The LED can be driven with higher current and higher input power by increasing heat dissipation, and more light flux can be obtained without overheating the LED die.
(3) More heat generating devices can be added very close to the LED die. This LED die includes other LED dies and embedded electronic components such as resistors, capacitors and transformers.

  The use of thermally conductive lenses applies to light emitting diodes (LEDs), ultraviolet (UV) light emitting LEDs and infrared light (IR) light emitting LEDs. The present invention can also be used for laser diodes and for other light generating devices that require a stable temperature for operation.

SUMMARY OF THE INVENTION An LED assembly with improved heat dissipation is comprised of a high power LED chip having a first surface and a second surface. The first surface of the LED chip is attached to the substrate, and the second surface is in intimate thermal contact with a translucent heat sink, which has a thermal conductivity greater than 30 W / m · K. Have Otherwise, the LED is in electrical contact with at least one electrical connection and a second electrical connection for supplying energy to the LED chip.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic cross-sectional view of an LED assembly having a light transmissive heat sink.
FIG. 2 is a schematic cross-sectional view of an alternative LED assembly having a light transmissive heat sink.
FIG. 3 is a schematic cross-sectional view of an alternative translucent heat sink.
FIG. 4 is a schematic cross-sectional view of an alternative LED assembly having a light transmissive heat sink.
FIG. 5 is a schematic cross-sectional view of a translucent heat sink having a molded refractive lens.
FIG. 6 is a schematic cross-sectional view of a translucent heat sink having a molded light guide such as a tapered prism.
FIG. 7 is a schematic view of a translucent heat sink with a grid of refractive lens features.
FIG. 8 is a schematic view of a translucent heat sink having a grid of light guide features.
FIG. 9 is a schematic view of a light transmissive heat sink having walls that are extended to bond with a substrate.

DETAILED DESCRIPTION OF THE INVENTION FIG. 1 is a schematic cross-sectional view of an LED assembly 10 having a light transmissive heat sink 12. The LED assembly 10 includes a high power LED chip 14 that has a first surface 16 and a second surface 18. The first surface 16 is attached to the substrate 20. The second surface 18 is in intimate thermal contact with the translucent heat sink 12. The translucent heat sink 12 has a thermal conductivity exceeding 30 W / m · K. Otherwise, the LED chip 14 is in electrical contact with at least one electrical connection 22 and a second electrical connection 24 for supplying energy to the LED chip 14.

The LED chip 14 can be any high power LED chip 14. The high power LED chip 14 as used herein means an LED chip having a power density of 1 W / mm ² or more. The concept of “LED chip” as used herein can be formed from a single die to meet such power density requirements and from multiple closely-grouped dies. It should be understood that it can also be formed. Thus, as used herein, the singular “LED chip” is meant to include an array of individual LED chips that are concentrated to provide 1 W or more per 1 mm ² of array area as a whole. It should also be understood that the term “LED chip” is meant to include both uncoated dies and phosphor-coated dies. This phosphor coating does not interfere with the electrical coupling with the LED die. Chip level light conversion by the phosphor sandwiched between the die and the light transmissive heat sink is completely performed when a heat dissipation process occurs. An advantageous LED chip 14 is a thin film surface emitting source. For example, a gallium nitride thin film surface emitter for blue or green light or a gallium nitride thin film surface emitter combined with a suitable phosphor to obtain white light is advantageous. Gallium arsenide is advantageous for infrared light, and gallium phosphide is advantageous for red light and yellow light. The light emitted from the LED chip 14 can be infrared light, visible light or ultraviolet light.

  The LED chip 14 has a first surface 16 attached to the substrate 20. The substrate 20 can be any of the commonly used substrates, including but not limited to a printed circuit board, a metal core circuit board, a ceramic substrate, a copper substrate or an aluminum substrate. Not. The LED chip 14 can be attached to the substrate 20 by a suitable bonding material (not shown). Solder and high temperature adhesives and epoxies are known for attaching LED chips to substrates.

  The substrate 20 also supports one or more electrical contacts (22, 24) for supplying power to the LED chip. In some cases, it is also common to form the one or more electrical traces on the substrate 20 and attach the LED chip 14 to receive power from the one or more electrical traces. The support substrate typically includes electrical connections such as, for example, conductive trace lines, mounting pads, other electrical circuit components, etc., for supplying power and possibly controlling the LED chip 14. FIG. 1 shows what is known as a flip chip attached to a substrate 20 for receiving power using two trace lines (22, 24) on the substrate 20 through a first surface 16. . Here, light is emitted from the second surface 18.

  The substrate 20 is further coupled to a heat sink along the edge or back surface, or to the support frame 26. Such heat sinks are typically metal bodies having heat dissipating components such as fins, pins, heat pipes, and similar heat and heat dissipation structures. Alternatively, a ceramic frame 27 can be used.

  The second surface 18 of the LED chip 14 is positioned so as to be in intimate thermal contact with the translucent heat sink 12. The translucency used here means having high translucency, and means translucency of 80% or more of the theoretical translucency of the whole material. It should be understood that translucency includes transparency. Here, transparent means inline translucency of 50% or more of theoretical inline translucency. Translucency also includes translucency, where translucency means inline transmissivity of 3% or more of theoretical inline transmissivity + 80% or more of theoretical translucency of the whole material It means total translucency. The translucent heat sink 12 thus acts as a window that transmits the light emitted by the LED chip 14 to the field to be illuminated. It is important that the light transmissive heat sink 12 is highly transmissive and is preferably light transparent. It is also important that the light transmissive heat sink 12 has a high thermal conductivity. The high thermal conductivity used here means a thermal conductivity exceeding 30 W / m · K. A window, such as a window made of glass or plastic low, has a thermal conductivity of 1.0 W / m · K or less, and thus effectively acts as a thermal insulator. Having a thermal conductivity of more than 30 W / m · K means that the window can act as an effective heat dissipation part relative to the LED chip.

  To be efficient, the light transmissive heat sink 12 is in direct contact with the LED chip 14 (possibly via a die or phosphor coating), or by using a thin bonding layer, for example. Must be in intimate contact. When direct contact is made, it is advantageous that 50% or more of the LED chips 14 are in contact with the translucent heat sink 12. Alternatively, if no electrical contact is required by the translucent heat sink 12 as in FIG. 1, a thin bonding layer (not shown) (not shown) can be used, for example, Clear silicone-based resins such as those used in the art can be used. Epoxy impregnated with a powder of translucent heat sink material or epoxy impregnated with a powder of indium-tin oxide can be used.

There are a plurality of advantageous translucent ceramics having a thermal conductivity of 30 W / m · K or more. These include aluminum nitride (AlN) (200 W / mK), sapphire (35 W / mK), alumina (Al ₂ O ₃ ) (30 W / mK), submicron alumina (30 W / mK), or nanoparticulate alumina (30 W / mK). mK) or magnesium oxide (MgO) (59 W / mK). Aluminum nitride includes normal particles of AlN (15-30 μm particles), submicron particles AlN or nanoparticle AlN. Each of these materials has advantages and disadvantages. Some of the translucent heat sink materials described above have high transmission even in the infrared region of 3-5 microns, which is an approximate peak emission point in the normal LED chip temperature operating region of 300K-400K. Appears as Relatively good IR transmitters include aluminum nitride (AlN), alumina (Al ₂ O ₃ ), and magnesium oxide (MgO). Spinel, AlON, YAG and yttria are also transparent in the 3-5 micron region. Other ceramics such as spinel, AlON, YAG and yttria are transparent in the visible region, but have low thermal conductivity (<30 W / mK), so aluminum nitride (AlN), alumina (Al ₂ O ₃ ) and oxidation Less desirable than magnesium (MgO). Also, some materials such as YAG are not very transmissive in the 3-5 micron IR region (80% or less). Translucent heat sinks add an additional cooling mechanism by radiating heat from the joint. Such joints do not exist in the case of plastic or glass lenses or windows. Thus, an advantageous translucent heat sink material is superior in further reducing self-heating by allowing enhanced IR radiation, and in particular, has a transmission greater than 80% in the 3-5 micron IR region. Have. Another material enhances light extraction from the LED die by having a refractive index lower than that of the associated die. Applicants recommend aluminum nitride for reasons of thermal conductivity and a coefficient of thermal expansion that matches well with that of many LED chips. Nano- or sub-micron alumina is advantageous for reasons of thermal conductivity and transparency. Different forms of alumina are advantageous for reasons of manufacturing costs. Magnesium oxide is advantageous because of its translucency and low refractive index.

  The translucent heat sink 12 may be a planar window and advantageously has an area that is significantly larger than the area of the second surface 18 of the LED chip. “Remarkably large” means that the area is four or more times larger. From a heat sink with a double linear dimension, it acts as a good heat sink and begins to spread heat over a quadruple area. Therefore, the peripheral part of the translucent heat sink acts as a heat dissipator. Additional active or passive heat dissipating components can be added along the edge of the light transmissive heat sink 12, such as a metal frame 26 or a heat dissipating component that expands or expands the surface area of the ceramic material. (Walls, fins and holes, etc.) can be added. An advantageous frame 26 is joined to the periphery of the substrate 20 so that heat conduction to the substrate 20 takes place. Frame 26 may be in close mechanical contact or by adhesive, silicone, brazing, frit, or another suitable bonding material (not shown) that is well bonded as a thin layer to conduct heat. It is tightly coupled to the translucent heat sink 12.

  The advantageous translucent heat sink 12 can extend substantially beyond the edge of the LED chip 14 as a radial flange 28. In this way, the entire peripheral flange region acts as a heat sink 12. The relative thickness of the light transmissive heat sink 12 and the size of the flange area can be determined by using heat management software to determine the heat flux from the LED chip 14 and the thermal conductivity of any bond filler material and the light transmissive heat sink 12. Given the size and shape and the thermal conductivity of the material of the translucent heat sink 12, it can be maximized. In general, the larger the relative area of the translucent heat sink 12 with respect to the LED chip 14, the greater the heat dissipation effect. As the volume of the light transmissive heat sink 12 increases, the thermal diffusion action increases. The greater the thermal conductivity of the material of the translucent heat sink 12, the greater the thermal diffusion effect. Any open capacity between the translucent heat sink 12, the LED 14, the substrate 20, and the support frame 26 (27) (in either case) is filled with a suitable thermally conductive and translucent filler. For example, the silicone resin 29 can be filled.

  FIG. 2 shows a schematic cross-sectional view of an alternative LED assembly 30 having a light transmissive heat sink 32. The light transmissive heat sink 32 can be formed to provide one of the electrical contacts of the LED chip. The first electrical contact 34 can again be supplied via the substrate 36. The second electrical contact 38 is supplied via a translucent heat sink 32. The second electrical contact 38 can also be formed as an embedded electrical contact formed on the surface of the translucent heat sink 32. This can be a thin wire, a deposited metal surface layer, or a metal surface formed on or within the translucent heat sink 32 to make electrical contact with the second surface 40 of the LED chip 42. It can be an injection. Since metals are generally not translucent, the area of the metal contacts must be minimized to maximize light transmission from the LED chip 42 through the translucent heat sink 32.

  FIG. 3 shows a schematic cross-sectional view of an alternative translucent heat sink 50. In another variation, the light transmissive heat sink 50 can be formed of two layers. The first layer is a translucent ceramic 52 having a thermal conductivity of 30 W / m · K or higher, and includes most of the translucent heat sink 50. The second layer 54 bonds between the LED chip and the translucent ceramic 52. The second layer 54 to be bonded is remarkably thin so as not to resist heat conduction from the LED chip to the translucent ceramic 52. This bonded second layer 54 is made of a light-transmitting electrical conductor, such as indium-tin oxide, or a metal that is thin enough to be light-transmitting and still conductive. Consists of sediment. By electrically connecting the LED chip and the conductive layer, a typical wire bonding connection can be eliminated, and the translucent heat sink can be in direct contact with the LED chip to provide better thermal conductivity. .

  FIG. 4 shows a schematic cross-sectional view of an alternative LED assembly 60 having a light transmissive heat sink 62. Similarly, a light transmissive heat sink is formed to provide one of the electrical contacts (trace, buried electrode or buried conductive layer) and the substrate is a second light transmissive that provides another electrical contact. The heat sink 64 can be replaced. Thus, the LED chip 66 includes a first light transmissive heat sink 62 (“window”) that supports the first electrical contact 68 and a second light transmissive heat sink that supports the second electrical contact 70. 64 ("substrate"). Therefore, the LED chip 66 is doubly cooled by the heat dissipation lens 62 and the heat dissipation substrate 64 and transmits light to both. The remaining intermediate volume between the first translucent heat sink 62 and the second translucent heat sink 64 is filled with a support ring 72 or of known silicone fillers used in LED assemblies. Among them, a filling material such as one silicone filler can be filled. Alternatively, one or both of the light transmissive heat sinks can be formed to span this intermediate space so as to contact the other light transmissive heat sink. Such a bridge satisfies both closure and heat dissipation. The translucent heat sink 62, substrate 64 or bridge coupling frame may be formed by a heat dissipating component 69, such as fins, fingers, holes, and other similar components to increase heat dissipation from the surface. .

  The outer surface of the translucent heat sink opposite to the LED chip can be formed by an optical component for focusing, diffusing, refracting or guiding light transmitted through the translucent heat sink. FIG. 5 is a schematic cross-sectional view of a light transmissive heat sink 80 on which a refractive lens 82 is formed. FIG. 6 shows a schematic cross-sectional view of a translucent heat sink 84 in which a light guide 86 such as a tapered prism is formed.

  Although a single LED having a light transmissive heat sink assembly has been described, an array of such assemblies is formed using a single substrate that supports an array of LED chips confined by a single light transmissive heat sink. can do. The one cover may include a grid of lenses or a grid of light guides. FIG. 7 shows a schematic cross-sectional view partially cut away from a light transmissive heat sink 90 having a grid of refractive lens components 92. These refractive lens components 92 are supplied from a grid of corresponding LEDs 91. The light transmissive heat sink 90 also has a bridge coupling wall 93 extending to the periphery for thermal coupling with the substrate 95. This is for transferring heat from the translucent heat sink 90 to the substrate 95. FIG. 8 shows a schematic cross-sectional view, partially cut away from a light transmissive heat sink 94 having a grid of light guiding components 96 fed to a grid 101 of corresponding LEDs. The substrate 97 also has a bridge coupling wall 99 that extends around the periphery of the substrate 97 for thermal coupling to the translucent heat sink 94. This is for transferring heat from the translucent heat sink 94 to the substrate 97.

  One advantage of extending the translucent heat sink from the LED chip is that the heat sink can be hermetically sealed. For example, an airtight frame such as a metal frame can seal and bridge the light-transmitting heat sink and the substrate, and the enclosed LED chip can be hermetically sealed. Sealed metal vias as is known in the art can be used to make an electrical connection inwardly through an airtight outer shell for electrical connection. In FIG. 9, a schematic cross-sectional view of an LED assembly 100 with a translucent heat sink 102 having an extended wall 104 for coupling to a substrate 106 is shown. The LED chip 108 is mounted on a (insulated) metal substrate 106. A support frame 104 surrounds the LED chip 108 and is in good thermal contact with the substrate 106. The support frame 104 may be co-formed with the substrate 106, formed as part of the light transmissive heat sink 102, or an encircling ring or similar that defines an interior space surrounding the LED chip 108 It can be a separately attached part, such as a body. The light transmissive heat sink 102 contacts the top surface of the LED chip 108 for heat input from the LED chip 108 and is bridged to the support frame 104 for conducting heat from the LED chip 108. The translucent heat sink 102 and the substrate 106 can be soldered, brazed, epoxy resin bonded, resin sealed, or similarly hermetically sealed along the joining walls of the frame 104. The advantage of the translucent heat sink material is that it can match the thermal expansion coefficient of the LED chip, substrate or bridge bonding material relatively close to the commonly used glass and plastic cover materials, so that the hermetic seal The stress can be reduced. In particular, the light supply from the LED chip can be supplied directly via a heat sink (eg, via the lens 92 or light guide 96), avoiding sealing problems and air tightness problems associated with other systems. The support frame 104 can also be used as an efficient thermal bridge between the light transmissive heat sink 102 and the substrate 106 if an airtight structure is not required.

  It is also possible to use a light conversion phosphor away from the LED chip and the light transmissive heat sink. For example, a light converting phosphor can be applied to the outer surface of a light transmissive heat sink, refractive lens component, or light guiding component.

  By diffusing heat from the LED chip across the translucent heat sink, the usable heat dissipation effect exerted on the LED can be quickly doubled depending on the area. When operating at a standard voltage, the LED chip can operate with 8-23% higher light generation efficiency. This can have a significant impact on the small lamp battery life, or it can have a significant impact on the overall electricity consumption of large (wall-sized) arrays. Alternatively, the LED chip can be operated with twice the current and efficiently maintaining the same chip (die) temperature. The efficiency (lm / W) does not increase, but the total amount of lumen released is approximately doubled. This has significant consequences in directional beam optics where the brightness of the light source is important, such as endoscopes, headlamps, or similar light beam systems.

  While the arrangements presently considered to be advantageous embodiments of the invention have been illustrated and described, those skilled in the art will recognize that various changes and modifications may be made without departing from the scope of the invention as defined by the appended claims. Understand that modifications can be made.

1 is a schematic cross-sectional view of an LED assembly having a light transmissive heat sink. FIG. 3 is a schematic cross-sectional view of an alternative LED assembly having a light transmissive heat sink. It is a schematic sectional drawing of an alternative translucent heat sink. FIG. 3 is a schematic cross-sectional view of an alternative LED assembly having a light transmissive heat sink. 1 is a schematic cross-sectional view of a light transmissive heat sink having a molded refractive lens. FIG. FIG. 2 is a schematic cross-sectional view of a light transmissive heat sink having a molded light guide such as a tapered prism. 1 is a schematic view of a translucent heat sink having a grid of refractive lens features. FIG. 1 is a schematic view of a light transmissive heat sink having a grid of light guide features. FIG. FIG. 3 is a schematic view of a light transmissive heat sink having walls that are extended to bond with a substrate.

Claims (50)

In the LED assembly,
A high power LED chip having a first surface and a second surface;
The first surface is attached to a substrate;
The second surface is in intimate thermal contact with a translucent heat sink having a thermal conductivity greater than 30 W / m · K;
The LED assembly, wherein the LED chip is in electrical contact with at least one first electrical connection and a second electrical connection for energizing the LED chip. In the LED assembly,
A high power LED chip having a first surface and a second surface;
The first surface is attached to a substrate;
The second surface is in intimate thermal contact with a translucent heat sink having a thermal conductivity greater than 30 W / m · K;
The total heat flux from the second surface of the LED chip to the light transmissive heat sink is four times the total heat flux from the second surface of the LED chip to the air in the absence of the light transmissive heat sink. Over
The LED assembly, wherein the LED chip is in electrical contact with at least one first electrical connection and a second electrical connection for energizing the LED chip. In the LED assembly,
A high power LED chip having a first surface and a second surface;
The first surface is attached to a substrate;
The second surface is in intimate thermal contact with a translucent heat sink having a thermal conductivity greater than 30 W / m · K;
The total heat flux from the second surface of the LED chip to the light transmissive heat sink is four times the total heat flux from the second surface of the LED chip to the air in the absence of the light transmissive heat sink. Over
The LED assembly, wherein the LED chip is in electrical contact with at least one first electrical connection and a second electrical connection for energizing the LED chip. In the LED assembly,
A high-power LED chip having a power density of 1.0 W / mm ² or more and having a first surface and a second surface;
The first surface is attached to a support substrate;
The second surface is in intimate thermal contact with a translucent heat sink having a thermal conductivity greater than 30 W / m · K;
The translucent heat sink has a periphery formed by a heat dissipating component;
The LED assembly, wherein the LED chip is in electrical contact with at least one first electrical connection and a second electrical connection for energizing the LED chip. In the LED assembly,
A high power LED chip having a first surface and a second surface;
The first surface is attached to a substrate;
The second surface is in intimate thermal contact with a translucent heat sink having a thermal conductivity greater than 30 W / m · K and has a transmission greater than 80% in the 3-5 micron IR region. And
The LED assembly, wherein the LED chip is in electrical contact with at least one first electrical connection and a second electrical connection for energizing the LED chip.   The LED assembly of claim 1, wherein the support frame having a thermal conductivity greater than 30 W / m · K is tightly coupled to the translucent heat sink.   The LED assembly of claim 6, wherein the support frame is formed as part of the support substrate.   The LED assembly of claim 6, wherein the support frame is formed as part of the light transmissive heat sink. The LED assembly according to claim 1, wherein the LED chip has a power density of 1.0 W / mm ² or more.   The LED assembly of claim 1, wherein the support substrate provides a first electrical connection.   The LED assembly of claim 10, wherein a substrate provides the first electrical connection and a second electrical connection for energizing the LED chip.   The LED assembly of claim 1, wherein the translucent heat sink provides the second electrical connection.   The LED assembly of claim 1, wherein the substrate is a translucent heat sink having a thermal conductivity greater than 30 W / m · K.   The LED assembly of claim 1, wherein a translucent heat sink provides a second electrical connection for energizing the LED.   The translucent heat sink includes a first layer including a translucent ceramic and a second layer including a translucent conductive layer intermediate the first layer and the second surface of the LED. Item 2. The LED assembly according to Item 1.   16. The LED assembly of claim 15, wherein the conductive layer is a conductive ceramic.   16. The LED assembly of claim 15, wherein the conductive layer is conductive ITO.   16. The LED assembly of claim 15, wherein the conductive layer is a conductive polymer.   The LED assembly according to claim 15, wherein the conductive layer is a conductive buried metal electrode.   The LED assembly of claim 15, wherein the conductive layer is a conductive deposited metal electrode layer.   The LED assembly of claim 1, wherein the translucent heat sink is made of aluminum nitride (AlN).   The LED assembly of claim 21, wherein the translucent heat sink is made of submicron particle aluminum nitride (AlN).   The LED assembly of claim 1, wherein the translucent heat sink comprises sapphire.   The LED assembly of claim 1, wherein the light transmissive heat sink is made of alumina.   25. The LED assembly of claim 24, wherein the light transmissive heat sink comprises submicron alumina.   25. The LED assembly of claim 24, wherein the light transmissive heat sink comprises nano alumina.   The LED assembly of claim 1, wherein the translucent heat sink comprises MgO.   The LED assembly of claim 1, wherein the light transmissive heat sink is optically formed to form an optical distribution of light received from the LED chip and transmitted through the light transmissive heat sink.   The LED assembly of claim 1, wherein the translucent heat sink includes conductive traces for supplying power to the LED chip.   The LED assembly of claim 1, wherein at least a portion of the translucent heat sink directly contacts the LED chip.   Between the LED chip and the light transmissive heat sink, a light transmissive and heat conductive intermediate layer of a material that allows light transmission and heat conduction from the LED chip to the light transmissive heat sink is disposed. The LED assembly of claim 1.   32. The LED assembly of claim 31, wherein the intermediate layer includes a bonding component (epoxy, silicone, high temperature adhesive) and a translucent ceramic powder implant.   32. The LED assembly of claim 31, wherein the translucent ceramic powder has 50% or more of the volume of the intermediate layer.   32. The LED assembly of claim 31, wherein the translucent ceramic powder has an average particle size of 0.01 microns to 1.0 microns.   The LED assembly of claim 1, wherein the translucent heat sink is held in a conductive peripheral frame.   The LED assembly of claim 1, wherein the translucent heat sink is bonded or brazed to a conductive peripheral frame.   36. The LED assembly of claim 35, wherein the peripheral frame is formed by a heat radiating component.   The LED assembly of claim 1, wherein the translucent heat sink has a surface molded with a refractive lens.   The LED assembly of claim 1, wherein the LED chip is a gallium nitride thin film emitter.   The LED assembly of claim 1, wherein the LED chip is a gallium arsenide thin film emitter.   The LED assembly of claim 1, wherein the LED chip is a gallium phosphide thin film emitter.   The LED assembly according to claim 1, wherein the intermediate material is a translucent silicone resin.   The LED assembly of claim 1, wherein the at least one electrical contact with the LED chip is a flat trace sandwiched between the LED chip and a portion of the translucent heat sink.   The LED assembly of claim 1, wherein the LED chip is secured to a support substrate that provides at least one electrical connection with the LED chip along a bottom surface of the LED chip.   The LED assembly according to claim 1, wherein the support substrate is formed of a translucent material having a thermal conductivity of greater than 30 W / m · K.   The LED assembly according to claim 1, wherein the LED chip is hermetically sandwiched between the support substrate and a light transmissive heat sink. A planar array of LED chips is disposed on a support substrate;
The LED assembly of claim 1, wherein a light transmissive heat sink covers the array of LED chips.   The LED assembly according to claim 1, wherein the translucent heat sink is hermetically sealed to the support substrate.   The LED assembly of claim 1, wherein the translucent heat sink includes a light guiding portion such as a tapered prism. In the LED assembly,
An LED chip sandwiched between a light-transmitting and thermally radiating cover and a light-transmitting and heat-radiating support substrate;
The cover and the support substrate are supported by a thermally conductive frame that includes heat dissipation components;
The frame and the support substrate are attached to the first surface of the heat insulating layer;
An electronic control assembly for the LED assembly is attached to the second side of the thermal insulation layer;
An LED assembly, wherein a heat dissipation component is formed adjacent to the electronic control assembly.

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